[taylorg009]

Why

"What the agent decided" (0.20.0) showed a line for 1 of 96 checkpointed commits on a real web-app repository since 2026-09-20. The rules assumed sessions that rarely happen:

• Test outcome by exit status, bare runs only. Agents pipe runs (vitest … 2>&1 | tail), so the status is the pipe's and nothing counted. The status was also wrong both ways: a denied permission read as a failure, and a run whose output said Tests 4 failed exited 0.
• Repo root from Edit/Write paths only. Agents that edit through python3 - <<EOF or cat > file had no root, so nothing was read.
• Two roots meant nothing. Long sessions work in several worktrees, and some of those carry the same repo paths.
• Subagents invisible. Entire 0.11.5 keeps their transcripts under tasks/<tool_use_id>/, and nothing read them.

What changes

• A test run's outcome comes from the runner's own summary line (vitest/jest Tests, pytest ===, cargo test result:, go ok/FAIL), read and never shown. A bare run with no summary still uses its status, unless it never ran.
• One run per command. A run followed by a step that puts files back (cp, mv, git apply/checkout/restore/stash, patch) is a probe and is skipped. T="path"; vitest run "$T" names path.
• A run names test files only when it targets nothing but files the change carries. "Failed on its last run" is dropped when the same runner passed later in the window.
• Root from Bash. A Bash call run in a known directory that names a changed file by its repo path gives that directory as the root. The directory is followed across calls; cd "$PWD" stays put. Temp folders are never a root.
• Two roots. When there are two roots, the one the last git commit ran in wins, if it's among them.
• Subagents. Their tool calls are read inside the parent's turn, right after the Agent call, for decisions only.

Evidence

The same 96 commits were replayed through checkpointFor with each commit's own files:

build	commits with a line
0.22.0	1 (a design note)
this branch	20: 13 with failed, then passed, 6 failed on its last run, 4 with a design note (a commit can have several)

I spot-checked lines by hand against the transcripts:

• Red check: a red check against swapped-in code no longer reads as "failed on its last run".
• Earlier false claim: a run followed by echo/tsc steps now counts, which fixed a "failed on its last run" claim that turned out false during this work.
• Directory runs: a run over a whole __tests__ folder no longer names one file.

Subagent transcripts are real. The repository's entire/checkpoints/v1 holds 50 tasks/<tool_use_id>/agent-<id>.jsonl files across 7 checkpoints written by Entire 0.11.5. So far all of them are read-only helper agents, so none adds a decision yet.

An independent review requested changes and then approved at 5540b0c. The fixes, each with a test that fails on the earlier code:

• A bare run that exits non-zero stays failed. Vitest Test Files/Errors and jest Test Suites: lines count as failures.
• go and cargo summary lines only ever mark a run as failed.
• The summary patterns no longer backtrack. pytest took 55 s on a 30k-character line before.
• cd/pushd are read with redirects stripped and with variables assigned earlier in the same command substituted, in order. popd, a bare cd, or a step that can't be read makes the directory unknown.
• Only test files are named, so a --config file isn't.
• A temp-folder root, such as an agent's scratchpad, is never the repo.

Tests: 422 passed (16 new cases in decisions.test.ts and checkpoint.test.ts, run against real git checkpoints).

🤖 Generated with Claude Code

[github-actions]

PR brief: 3 agent commits · 8 of 25 test files reach this diff

Run at least these. Selection is a safe superset; it never marks a test safe to skip.

Summary	PR #58 at be36328
Changed	7 files: 4 mapped to 20 symbols, 3 ignored by policy
Tests reached	8 of 25 ▮▮▮▮▮▮▯▯▯▯▯▯▯▯▯▯▯▯▯▯ 32% of the suite
Downstream code	8 files, 23 dependents · review effort high
Intent	3 of 3 commits attributed by trailer (claude-code)
Reviewed by	no reviewer other than the author (taylorg009) so far · the 12 changed and reached files were last changed by Taylor Gagne (59 commits in 10 files), Taylor (15 commits in 10 files) · Taylor has no prior commit in 2 of the 12 files this change touches or reaches: src/checkpoint-write.ts, src/owners.ts
Symbols	12 changed, 10 added, 1 removed within the diff
Since push 5540b0c	1 new commit, 0 changed files, 0 tests reached
Compared against	base 64f5992

What each commit did

Commit	Intent	Files	Reaches	Ran before push
fefd69d feat(decisions): read test outcomes, script edits and subag…	claude-code by Co-authored-by	7 files	8 files, 8 tests
5540b0c fix(decisions): never pass a failed run; lose the directory…	claude-code by Co-authored-by	5 files	8 files, 8 tests
be36328 fix(decisions): substitute a variable only from assignments…	claude-code by Co-authored-by	2 files	8 files, 8 tests

Claims checked

• refuted: PR body names echo. no changed symbol bears it and no changed line contains it (phantom change).
• refuted: PR body names tsc. no changed symbol bears it and no changed line contains it (phantom change).
• consistent: bash removed from src/decisions.test.ts. 1 static caller in the base graph, all in files this diff changes: src/decisions.test.ts.
• consistent: the narrative names the changed code. all 3 files with symbol changes are named.

What each changed file reaches

Read	Changed file	Change	Reaches	Tests
1	decisions.ts	Block changed, result changed, decisionsIn changed, +4	8 files	8
with decisions.ts	checkpoint.ts	checkpointFor changed, leaves changed, repoRoot changed, +11	8 files	7
2	checkpoint.test.ts	test code, selected directly		1
3	decisions.test.ts	test code, selected directly		1
	3 files under the repo root	ignored by policy		0

Paths above are under src/ unless shown in full.

Tests to run (8)

• src/brief.test.ts
• src/checkpoint-write.test.ts
• src/checkpoint.test.ts
• src/comment.test.ts
• src/decisions.test.ts
• src/mcp.test.ts
• src/owners.test.ts
• src/sessions.test.ts

Blast radius by changed file: 23 dependents

• decisions.ts reaches buildBrief (brief.ts), checkpoint-write.ts, cli.ts, comment.ts, index.ts, callTool, handleRequest, serveStdio (mcp.ts), +2 files
• checkpoint.ts reaches buildBrief (brief.ts, calls checkpointFor), checkpoint-write.ts (imports sessions.ts, which imports it), cli.ts (imports it), comment.ts (imports it), index.ts (re-exports it), callTool, handleRequest, serveStdio (mcp.ts, callTool calls buildBrief in brief.ts, which calls checkpointFor), +2 files

_{blastline 0.23.0. Selection is advisory unless your workflow gates on it. How selection works. Graph 992ac5e. change-context budget 43432: omitted 0 impacts, 751 context entries (truncated); symbols are classified within the diff only. Intent: 0 of 3 commits, 3 attributed by trailer.}